1. Field of the Invention
The present invention relates to a headlamp cleaning device which ejects cleaning fluid stored in a tank onto a headlamp through a nozzle.
2. Related Background Art
Conventional headlamp cleaning devices eject cleaning fluid onto a headlamp through a nozzle only for the time period during which the driver continues to push a switch. This conventional headlamp cleaning device would possibly consume a wasteful quantity of the cleaning fluid since the quantity of the cleaning fluid is determined by the driver's manual operations of the switch.
There is another type of conventional headlamp cleaning device which ejects cleaning fluid stored in a tank onto a headlamp through a nozzle by driving a motor for a predetermined time period when the driver pushes a switch for the motor. When the headlamp cleaning device of this type is operated, the cleaning liquid will be ejected for a predetermined time period, so that the quantity of the cleaning liquid is thereby constantly determined. As a result, the headlamp cleaning device does not consume any excessive quantity of the cleaning fluid or electric power.
Generally, however, when the value of the power source voltage supplied to the motor is decreased due to turning on an air conditioning apparatus and/or headlamp which requires relatively large voltage, or deterioration of the power source itself, the rotational speed of the motor also decreases and the revolutional number of the pump decreases thereby, both which cause the rotational power of the motor to become weaker. For this reason, the conventional headlamp cleaning device suffers from a problem in that the quantity of the cleaning fluid ejected for every single operation will be decreased to thereby decline the motor's cleaning ability because the motor is driven for a predetermined constant time period at one operation according to the conventional headlamp cleaning device.
On the other hand, in order to improve the cleaning capacity of the conventional headlamp cleaning device operated at a lower voltage, the driving time for the motor for one cleaning operation may be set at a longer time period. However, the headlamp cleaning device ejects excessive amount of cleaning fluid when the voltage is at a higher level, thereby consuming wasteful quantities of the cleaning fluid and the operating electric power.